During an episode of KBS drama "Big" that was aired on the 19th of June, featured a fight between Gil Da Ran (Lee Min Jung) and Lee Se Young (Jang Hee Jin). Specifically, Gil Da Ran warns Lee Se Young to stay away from Seo Yoon Jae (Gong Yoo).

Gil Da Ran stops by the house she decorated with Kang Kyung Joon to be a 'newly-wed-house.' Kang Kyung Joon had bought the house with Seo Yoon Jae's money without Gil Da Ran's permission because he was about to lose the house his mother had left him. After Gil Da Ran forgives him, they had decorated the house together. 

In the midst of her packing, Gil Da Ran runs into Lee Se Young who also comes to the house. Gil Da Ran tells Lee Se Young, "Are you really thinking about marrying Seo Yoon Jae?" Lee Se Young, who is upset, beats around the bush and does not address Gil Da Ran's question.

Gil Da Ran continues, "No part of me wants to help you even a little bit but I want to warn you from something that big. You're 31, right? What do you feel when you see a 19 year old high school student? Could you be attracted to him? Right now, there is a very immature little boy inside of Seo Yoon Jae."

Lee Se Young then replies, "I know Yoon Jae has changed a lot ever since his accident but I still like him regardless. I'm not going to give up like you."

Dumbfounded at Lee Se Young's answer, Gil Da Ran suddenly feels the need to protect the young and naive 19 year old boy Kang Kyung Joon. Gil Da Ran snaps at Lee Se Young with the words, "Get up, that's my sofa. Don't ever come back. If you come back, I will beat you up until black tea turns into green tea," and kicks her out of the house.